From: Bryan Schumaker Subject: Re: [PATCH v2 2/2] NFS: Send SIGIO on lost locks Date: Mon, 18 Jul 2011 13:58:46 -0400 Message-ID: <4E247456.4040207@netapp.com> References: <1311011616-11503-1-git-send-email-bjschuma@netapp.com> <1311011616-11503-2-git-send-email-bjschuma@netapp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Trond.Myklebust@netapp.com, linux-nfs@vger.kernel.org, Thomas Gleixner , Ingo Molnar , David Howels , Steve French , Miklos Szeredi , linux-fsdevel@vger.kernel.org To: bjschuma@netapp.com Return-path: Received: from mx2.netapp.com ([216.240.18.37]:49900 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751149Ab1GRR6s (ORCPT ); Mon, 18 Jul 2011 13:58:48 -0400 In-Reply-To: <1311011616-11503-2-git-send-email-bjschuma@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: I fixed Ingo's email address in the patch, it should be "@redhat.com" and not "@redahat". Sorry about that. - Bryan On 07/18/2011 01:53 PM, bjschuma@netapp.com wrote: > From: Bryan Schumaker > > If we discover that the server has lost a client's lock, we send SIGIO to the > client application and let the application decide the best method of handling > the error. > > This could also be done by sending the SIGLOST signal to the userland > application. Most architectures have a definition of SIGIO commented out in > their signal.h. In most cases, SIGLOST would be defined to the same value as > SIGIO. A new signal could be created, but there are no available slots before > SIGRTMIN. > > Signed-off-by: Bryan Schumaker > CC: Trond Myklebust > CC: Thomas Gleixner > CC: Ingo Molnar > CC: David Howels > CC: Steve French > CC: Miklos Szeredi > CC: linux-fsdevel@vger.kernel.org > --- > Documentation/kernel-parameters.txt | 7 +++++++ > fs/nfs/nfs4_fs.h | 2 ++ > fs/nfs/nfs4proc.c | 21 +++++++++++++++++++++ > fs/nfs/nfs4state.c | 14 ++++++++++++++ > fs/nfs/read.c | 9 +++++++++ > fs/nfs/write.c | 7 +++++++ > 6 files changed, 60 insertions(+), 0 deletions(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index fd248a31..988ebdc 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -1593,6 +1593,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > of returning the full 64-bit number. > The default is to return 64-bit inode numbers. > > + nfs.enable_sigio= > + [NFSv4.1] enable sending SIGIO to applications. > + If true, the NFS client will send SIGIO to applications > + when a lost file lock is detected. If false, the client > + will attempt to recover the lock. > + The default is to send SIGIO. > + > nfs.nfs4_disable_idmapping= > [NFSv4] When set, this option disables the NFSv4 > idmapper on the client, but only if the mount > diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h > index c30aed2..8fa02af 100644 > --- a/fs/nfs/nfs4_fs.h > +++ b/fs/nfs/nfs4_fs.h > @@ -163,6 +163,7 @@ struct nfs4_lock_state { > struct list_head ls_locks; /* Other lock stateids */ > struct nfs4_state * ls_state; /* Pointer to open state */ > #define NFS_LOCK_INITIALIZED 1 > +#define NFS_LOCK_INVALID 2 > int ls_flags; > struct nfs_seqid_counter ls_seqid; > struct rpc_sequence ls_sequence; > @@ -346,6 +347,7 @@ extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state > extern void nfs4_put_open_state(struct nfs4_state *); > extern void nfs4_close_state(struct path *, struct nfs4_state *, fmode_t); > extern void nfs4_close_sync(struct path *, struct nfs4_state *, fmode_t); > +extern int nfs4_validate_lock_stateid(struct nfs4_state *, struct nfs_lock_context *); > extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t); > extern void nfs4_schedule_lease_recovery(struct nfs_client *); > extern void nfs4_schedule_state_manager(struct nfs_client *); > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index f37218b..bb29384 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -4462,6 +4462,8 @@ out: > } > > #if defined(CONFIG_NFS_V4_1) > +bool enable_sigio = true; > + > static int nfs41_lock_expired(struct nfs4_state *state, struct file_lock *request) > { > int status; > @@ -4472,10 +4474,29 @@ static int nfs41_lock_expired(struct nfs4_state *state, struct file_lock *reques > status = nfs41_test_stateid(server, stateid); > if (status == NFS_OK) > return 0; > + > nfs41_free_stateid(server, stateid); > lock_state->ls_seqid.flags &= !NFS_SEQID_CONFIRMED; > + > + if (enable_sigio) { > + u32 secid; > + struct siginfo info = { > + .si_signo = SIGIO, > + .si_code = __SI_SIGLOST, > + .si_errno = -ENOLCK, > + }; > + lock_state->ls_flags |= NFS_LOCK_INVALID; > + security_task_getsecid(current, &secid); > + kill_pid_info_as_uid(SIGIO, &info, request->fl_nspid, > + current_cred()->uid, current_cred()->euid, secid); > + return 0; > + } > return nfs4_lock_expired(state, request); > } > + > +module_param(enable_sigio, bool, 0644); > +MODULE_PARM_DESC(enable_sigio, "Send SIGIO to an application when a lost lock" > + "is detected instead of attempting recovery"); > #endif > > static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request) > diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c > index 5d744a5..101d9b4 100644 > --- a/fs/nfs/nfs4state.c > +++ b/fs/nfs/nfs4state.c > @@ -725,6 +725,20 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_p > return NULL; > } > > +int nfs4_validate_lock_stateid(struct nfs4_state *state, struct nfs_lock_context *lock_ctx) > +{ > + int valid = 1; > + struct nfs4_lock_state *lock_state; > + > + spin_lock(&state->state_lock); > + lock_state = __nfs4_find_lock_state(state, lock_ctx->lockowner, lock_ctx->pid, NFS4_ANY_LOCK_TYPE); > + if (lock_state != NULL) > + valid = (lock_state->ls_flags & NFS_LOCK_INVALID) == 0; > + spin_unlock(&state->state_lock); > + nfs4_put_lock_state(lock_state); > + return valid; > +} > + > /* > * Return a compatible lock_state. If no initialized lock_state structure > * exists, return an uninitialized one. > diff --git a/fs/nfs/read.c b/fs/nfs/read.c > index c394662..c597f9e 100644 > --- a/fs/nfs/read.c > +++ b/fs/nfs/read.c > @@ -468,6 +468,15 @@ static void nfs_readpage_release_partial(void *calldata) > void nfs_read_prepare(struct rpc_task *task, void *calldata) > { > struct nfs_read_data *data = calldata; > + struct nfs4_state *state = data->args.context->state; > + struct nfs_lock_context *lock_context = data->args.lock_context; > + > + if (!nfs4_validate_lock_stateid(state, lock_context)) { > + task->tk_status = -EIO; > + task->tk_action = NULL; > + return; > + } > + > > if (nfs4_setup_sequence(NFS_SERVER(data->inode), > &data->args.seq_args, &data->res.seq_res, > diff --git a/fs/nfs/write.c b/fs/nfs/write.c > index 7f8732e..49ca975 100644 > --- a/fs/nfs/write.c > +++ b/fs/nfs/write.c > @@ -1114,7 +1114,14 @@ out: > void nfs_write_prepare(struct rpc_task *task, void *calldata) > { > struct nfs_write_data *data = calldata; > + struct nfs4_state *state = data->args.context->state; > + struct nfs_lock_context *lock_context = data->args.lock_context; > > + if (!nfs4_validate_lock_stateid(state, lock_context)) { > + task->tk_status = -EIO; > + task->tk_action = NULL; > + return; > + } > if (nfs4_setup_sequence(NFS_SERVER(data->inode), > &data->args.seq_args, > &data->res.seq_res, 1, task))